

#include <stdio.h>
#include <unistd.h>
#include <assert.h>

int g_val = 99;

int main(){
  pid_t id = fork();
  assert(id >= 0);
  if(id == 0){
    while(1){
      printf("子进程, pid:%d, ppid:%d, g_val:%d, &g_val:%p\n",getpid(), getppid(), g_val, &g_val);
      sleep(1);
    }
  }
  else{
    while(1){
      printf("父进程, pid:%d, ppid:%d, g_val:%d, &g_val:%p\n",getpid(), getppid(), g_val, &g_val);
      sleep(2);
    }
  }
}
